XCF.php

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<?php
class XCFHandler extends BitmapHandler {

        function mustRender( $file ) {
                return true;
        }

        function getThumbType( $ext, $mime, $params = null ) {
                return array( 'png', 'image/png' );
        }

        function getImageSize( $image, $filename ) {
                return self::getXCFMetaData( $filename );
        }

        static function getXCFMetaData( $filename ) {
                # Decode master structure
                $f = fopen( $filename, 'rb' );
                if( !$f ) {
                        return false;
                }
                # The image structure always starts at offset 0 in the XCF file.
                # So we just read it :-)
                $binaryHeader = fread( $f, 26 );
                fclose($f);

                # Master image structure:
                #
                # byte[9] "gimp xcf "  File type magic
                # byte[4] version      XCF version
                #                        "file" - version 0
                #                        "v001" - version 1
                #                        "v002" - version 2
                # byte    0            Zero-terminator for version tag
                # uint32  width        With of canvas
                # uint32  height       Height of canvas
                # uint32  base_type    Color mode of the image; one of
                #                         0: RGB color
                #                         1: Grayscale
                #                         2: Indexed color
                #        (enum GimpImageBaseType in libgimpbase/gimpbaseenums.h)
                try {
                        $header = wfUnpack(
                                  "A9magic"     # A: space padded
                                . "/a5version"  # a: zero padded
                                . "/Nwidth"     # \
                                . "/Nheight"    # N: unsigned long 32bit big endian
                                . "/Nbase_type" # /
                        , $binaryHeader
                        );
                } catch( MWException $mwe ) {
                        return false;
                }

                # Check values
                if( $header['magic'] !== 'gimp xcf' ) {
                        wfDebug( __METHOD__ . " '$filename' has invalid magic signature.\n" );
                        return false;
                }
                # TODO: we might want to check for sane values of width and height

                wfDebug( __METHOD__ . ": canvas size of '$filename' is {$header['width']} x {$header['height']} px\n" );

                # Forge a return array containing metadata information just like getimagesize()
                # See PHP documentation at: http://www.php.net/getimagesize
                $metadata = array();
                $metadata[0] = $header['width'];
                $metadata[1] = $header['height'];
                $metadata[2] = null;   # IMAGETYPE constant, none exist for XCF.
                $metadata[3] = sprintf(
                        'height="%s" width="%s"', $header['height'], $header['width']
                );
                $metadata['mime'] = 'image/x-xcf';
                $metadata['channels'] = null;
                $metadata['bits'] = 8;  # Always 8-bits per color

                assert( '7 == count($metadata); # return array must contains 7 elements just like getimagesize() return' );

                return $metadata;
        }

        protected static function getScalerType( $dstPath, $checkDstPath = true ) {
                return "im";
        }
}